@article{fdi:010035684,
  title = {{T}emporal variability in phytoplankton pigments, picoplankton and coccolithophores along a transect through the {N}orth {A}tlantic and tropical southwestern {P}acific},
  author = {{D}andonneau, {Y}ves and {M}ontel, {Y}ves and {B}lanchot, {J}ean and {G}iraudeau, {J}. and {N}eveux, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}iogeochemical processes in the sea are triggered in various ways by chlorophyll-containing phytoplankton groups. {W}hile the variability of chlorophyll concentration at sea has been observed from satellites for several years, these groups are known only from cruises which are limited in space and time. {T}he {G}eochemistry, {P}hytoplankton and {C}olor of the {O}cean programme ({G}e{P}&{CO}) was set up to describe and understand the variability of phytoplankton composition on large spatial scales under a multi-year sampling strategy. {I}t was based on sea-surface sampling along the route of the merchant ship {C}ontship {L}ondon which travelled four times a year from {L}e {H}avre ({F}rance) to {N}oumea ({N}ew {C}aledonia) via {N}ew {Y}ork, {P}anama and {A}uckland. {O}bservations included the measurement of photosynthetic pigments, counts of picoplanktonic cells by flow cytometry ({P}rochlorococcus, {S}ynechococcus, and picoeucaryotes) and counting and identification of coccolithophores. {T}he results confirmed that tropical areas have low seasonal variability and are characterized by relatively high divinyl-chlorophyll a and zeaxanthin concentration and that the variability is strongest at high latitudes-where the phytoplankton biomass and population structure are found to have large seasonal cycles. {T}hus, the spring bloom in the {N}orth {A}tlantic and an austral winter bloom north of {N}ew {Z}ealand are marked by chlorophyll concentrations which are often higher than 0.5 mu g l(-1) and by high concentration of fucoxanthin (a pigment used as an indicator for diatoms), while summer populations are dominated by {P}rochlorococcus sp. and have low chlorophyll concentrations. {A}part from this yearly bloom at temperate latitudes, fucoxanthin is scarce, except in the equatorial upwelling zone in the eastern {P}acific {O}cean, where it is found in moderate amounts. {I}n this region, relatively high chlorophyll concentrations extend generally as far as 14 degrees {S} and do not respond to the seasonal strengthening of the equatorial upwelling during the austral winter. {P}rochlorococcus, which is known to dominate in oligotrophic tropical seas and to disappear in cold conditions, in fact has its minimum during the spring bloom in the {N}orth {A}tlantic, rather than during the winter. {C}occolithophores are ubiquitous, showing a succession of species ill response to oceanic conditions and provinces. 19'{H}exanoyloxyfucoxanthin, the pigment generally considered as all indicator of coccolithophores, is relatively abundant at all times and in all regions, but its abundance is generally not tightly correlated with that of coccolithophores. {T}he regional differences revealed by these results are in overall agreement with {L}onghurst's division of the ocean into ecological provinces. (c) 2006 {E}lsevier {L}td. {A}ll rights reserved.},
  keywords = {},
  booktitle = {},
  journal = {{D}eep {S}ea {R}esearch {P}art {I} {O}ceanographic {R}esearch {P}apers},
  volume = {53},
  numero = {4},
  pages = {689--712},
  ISSN = {0967-0637},
  year = {2006},
  DOI = {10.1016/j.dsr.2006.01.002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010035684},
}